Many engineering structures are subjected to the simultaneous conditions of an applied stress (or load) and a corrosive environment. This combination of stress and corrosion can lead to material failures that might not occur from either condition alone, or that would take longer to occur from either condition alone. The resulting material failure is known as “stress corrosion cracking”, and can cause structural failure of equipment such as boilers, pressure vessels, oil and gas piping, bridges, vehicles, and aircraft.
There are a number of existing methods for measuring susceptibility to stress corrosion cracking, and for measuring crack propagation rates. One limitation of existing methods is that their detection of crack propagation rates is limited. A typical limit of 10−11 meters per second is too high to determine whether stress corrosion cracking will lead to failure of highly resistive materials over a long time period. Another limitation of existing methods is that they are not easily implemented as sensors for real-time real-world monitoring.